Various devices including integral circuits, semiconductors, electronic, photoelectric, display, magnetic or electromechanical devices and optical lens (e.g., prism sheet and lenticular lens sheet) involve micropatterns which have been conventionally formed by photolithography. However, the photolithography requires a complicated patterning process and a high production cost, and is not suitable for forming ultramicropatterns having a line width of below 100 nm.
Therefore, there has been recently developed a nano-imprint lithography wherein a pattern of a hard mold, e.g., a Si mold, is replicated on a thermoplastic polymer layer. This method is advantageous in fabricating a pattern having a narrow line width of about 7 nm owing to the hardness of the mold (see S. Y. Chou et al., J. Vac. Sci. Technol. B15, 2897(1997)). However, this nano-imprint lithography has the problems that the mold is not easily lifted off from the substrate and it may break during the pressurizing procedure under a high temperature and pressure condition.
Other non-traditional lithographic methods for fabricating micropatterns include micro-contact printing (mCP), micro-molding in capillaries (MIMIC), micro-transfer molding (mTM), soft molding, and capillary force lithography (CFL) methods. These methods generally employ a mold made of an elastic polymer such as polydimethylsiloxane (PDMS), which is a silicon rubber type, but the PDMS mold has poor dimensional and chemical stabilities so that it cannot achieve a narrow pattern width of less than 500 nm.
Modified PDMS's including h-PDMS (hard PDMS) and hv-PDMS (photo-curable PDMS) have been developed to solve the problem of PDMS. However, h-PDMS still suffers from brittleness, low elongation at break, and poor conformal contact with a substrate (see Odom, Y. W. et al, Langmuir, 18, 5314-5320 (2002)), and hv-PDMS does not have enough modulus to replicate fine pattern below 100 nm even thouth troduced to overcome the aforementioned some limitations of conventional PDMS (see J. Am. Chem. Soc. 125, 4060-4061 (2003)).